In any city, in any country, go to any mental institution or halfway house you can get yourself to. When you reach the front desk, ask to visit someone who calls himself "The Holder of Deception." The worker will look at you with an expression of shock on her face. Then, with superhuman speed she will attack you with her baton. If you are not knocked unconscious by the first blow, flee the city, for they will know what you are after.
When your consciousness returns, you will be in a magnificent courtyard on a starry night. There will be a great stone staircase that appears to ascend to the heavens themselves. Climb this staircase, but never look behind you. If you do, the stairs will begin to crumble and you will plummet into the void for an eternity.
After what will seem like days of climbing, you will come to a landing overlooking a great marble amphitheater styled in the ancient Greek fashion. Descend to the bottom of the amphitheater.
An old man in opalescent robes will be waiting for you on a dais in the center. This storied old man will be lecturing as if there was a great crowd - however, you must not listen to him, for not a word he speaks is true. If you are drawn in by his charismatic speaking, your mind will be completely subjugated by his deception and you will be his slave for eternity. He will only react to one question: "What is the only truth you are permitted to speak of?"
The man will look down at you with an expression of great sadness. He will then impart on you a story that will shake the very foundations of your soul with great sorrow, but will leave you knowing one important truth: the number itself is not as it seems. He will then motion you towards an exit from the amphitheater, and continue his lecture. Turn away from him quickly, for you will now be able to see the legions of horrific, twisted demons sitting on the seats of the amphitheater.
Do not gaze towards any of them longer than a moment, or else they will tear you apart and add you to their collection of souls. Walk to the exit as quickly as possible. There will be a great grimoire on a stand next to the door. Take the grimoire and exit through the door. You will find yourself in the back alley behind the asylum.
The grimoire you clutch, with its pages firmly strapped shut and locked with a great steel padlock, is Object 20 of 538. If you wish to see past the deception and reunite them, you must find the key.